Samsung PM991a 256GB thermal throttling

I bought 64GB steam deck version and i changed it for samsung pm991a 256GB nvma and made a dual boot from it.

I noticed a throttling issue while performing tests steamOS (kdismark) and windows 11 (cristaldiskmark).

According to this forum

https://www.dell.com/community/Inspiron-...

and some others stuff on reddit. I assume this nvma model have a throttling issue. Question is how to solve the problem? I swapped ESD shield without damaging it so I think I did everything correctly. I was wondering if putting 1mm thermal pad inside of ESD shield (if it fit eventually) or to give some thermal pad on shield.

Maybe this would be only temporary solution not worth an effort. I'm planning to use win 11 on SD for photoshop and premiere pro video clipping since I don't have a pc nor suitable laptop for this.

Second option is to change this nvma to sabrent rocket and use that samsung with case as portable disk - I hate waste my electronics.

As I try to figure out what to do I came with an idea of buying a copper heatsink from aliexpress like this

While in looking at various yt clips from removing metal plate I noticed there is no contact between sdd and metal plate

I don't know is it good or is it would be better that ssd had that contact like copper heat sink -> thermal pad -> metal shield. or maybe it will be too much because other components transfer their heat to that metal shield. With additional component it may be too much. Dunno

It turned out that I have a samsung pm991 in my work laptop so I ran some tests and, I must say, I felt relief. It isn't problem with my steam deck, with that I just slided out that foil from stock 64GB disk and put new disk in it. It's just because this samsung pm991 works this way. It overheats.

Solution for that is to use some sort of heat sink. I ordered one from aliexpress. We well see.

Another test made on steam deck (windows 11)